BQ2092_15 Datasheet, PDF (17/30 Pages) Texas Instruments – Gas Gauge IC with SMBus-Like Interface

Obsolete Device
bq2092
WRINH should be set at the time of pack assembly and
tested to prevent special read-write registers from acci-
dental over-writing.
The EDVF values are:
FLAGS1 Bits
The Valid Discharge flag (VDQ), bit 3, is set when a
valid discharge is occurring (discharge cycle valid for
learning new full charge capacity) and cleared if a
partial charge is detected, EDV1 is asserted when T <
0°C, or self-discharge accounts for more than 256mAh of
the discharge.
765432
-
-
-
-
-
-
Where EDVF is:
0 VQ = 1 and Voltage > EDVF
1
0
- EDVF
The VDQ values are:
1 Voltage < EDVF and SEDV = 0
FLAGS1 Bits
7654
3
210
-
-
-
- VDQ -
-
-
Where VDQ is:
0 Self-discharge is greater than 256mAh,
EDV1 = 1 when T < 0°C or VQ = 1
1 On first discharge after RM=FCC
The Stop EDV flag (SEDV), bit 2, is set when the
discharge current > 6.15A and cleared when the
discharge current falls below 6.15A.
The SEDV values are:
FLAGS1 Bits
76543
2
10
-
-
-
-
- SEDV -
-
Where SEDV is:
0 Current < 6.15A
1 Current > 6.15A
The First End-of-Discharge Voltage flag (EDV1), bit 1, is
set when Voltage < EDV1 = 1 if SEDV = 0 and cleared
when VQ = 1 and Voltage > EDV1.
The EDV1 values are:
FLAGS1 Bits
765432
1
0
-
-
-
-
-
- EDV1 -
Software Reset
The bq2092 can be reset over the serial port by confirm-
ing that the WRINH bit is set to zero in FLAGS1, writ-
ing MaxError (0x0c) to any value other than 2, and writ-
ing the reset register (0x44) to 8009, causing the bq2092
to reinitialize and read the default values from the
external EEPROM.
Error Codes and Status Bits
Error codes and status bits are listed in Table 7 and
Table 8, respectively.
Programming the bq2092
The bq2092 requires the proper programming of an
external EEPROM for proper device operation. Each
module can be calibrated for the greatest accuracy, or
general “default” values can be used. A programming
kit (interface board, software, and cable) for an IBM-
compatible PC is available from Unitrode. Please
contact Unitrode for further details
The bq2092 uses a 24LC01 or equivalent serial
EEPROM for storing the various initial values, calibra-
tion data, and string information. Table 1 outlines the
parameters and addresses for this information. Tables 9
and 10 detail the various register contents and show an
example program value for an 1800mAh NiMH battery
pack, using a 50mΩ sense resistor.
Where EDV1 is:
0 VQ = 1 and Voltage > EDV1
1 Voltage < EDV1 and SEDV = 0
The Final End-of-Discharge Voltage flag (EDVF), bit 0, is
set when Voltage < EDVF = 1 if SEDV = 0 and cleared
when VQ = 1 and Voltage() > EDVF.
17